KR20090030903A - Backlight unit and liquid cristal display device usimg the same - Google Patents

Backlight unit and liquid cristal display device usimg the same Download PDF

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Publication number
KR20090030903A
KR20090030903A KR1020070096571A KR20070096571A KR20090030903A KR 20090030903 A KR20090030903 A KR 20090030903A KR 1020070096571 A KR1020070096571 A KR 1020070096571A KR 20070096571 A KR20070096571 A KR 20070096571A KR 20090030903 A KR20090030903 A KR 20090030903A
Authority
KR
South Korea
Prior art keywords
liquid crystal
light
lamp
guide plate
light guide
Prior art date
Application number
KR1020070096571A
Other languages
Korean (ko)
Inventor
이태희
Original Assignee
엘지디스플레이 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 엘지디스플레이 주식회사 filed Critical 엘지디스플레이 주식회사
Priority to KR1020070096571A priority Critical patent/KR20090030903A/en
Publication of KR20090030903A publication Critical patent/KR20090030903A/en

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0051—Diffusing sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
    • G02B6/007—Incandescent lamp or gas discharge lamp
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133524—Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2201/00—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
    • G02F2201/50—Protective arrangements
    • G02F2201/503—Arrangements improving the resistance to shock

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Planar Illumination Modules (AREA)

Abstract

A backlight unit and a liquid crystal display device using the same are provided to improve a light guide plate and a lamp housing, thereby preventing light leakage and wrinkles of an optical sheet, thereby preventing damage of a lamp due to vibration. A liquid crystal panel displays an image by controlling light transmission of liquid crystal. A color filter array substrate is comprised of a color filter, a common electrode, and a black matrix. A lower polarizing film(210) faces the second optical sheets(116). The lower polarizing film is on a rear surface of a transistor array panel. The lower polarizing film polarizes light applied from the optical sheets. On the rear surface of the color filter array substrate, an upper polarizing film(212) is adhered. A panel guide(202) is laminated on a bottom cover(102) and a lamp housing(110). A top cover(214) assembles the panel guide and the bottom cover.

Description

BACKLIGHT UNIT AND LIQUID CRISTAL DISPLAY DEVICE USIMG THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a backlight unit capable of preventing cracking and wrinkles of an optical sheet and a liquid crystal display device using the same.

Recently, various flat panel display devices that can reduce weight and volume, which are disadvantages of cathode ray tubes, have emerged. Such a flat panel display includes a liquid crystal display, a field emission display, a plasma display panel, a light emitting device, and the like.

The liquid crystal display device displays an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the liquid crystal display includes a liquid crystal panel having a liquid crystal cell, a back light unit for irradiating light to the liquid crystal panel, and a driving circuit for driving the liquid crystal cell.

In this case, since the liquid crystal panel of the liquid crystal display device is a light-receiving element that displays an image by controlling the amount of light source coming from the outside, a backlight unit, which is a separate light source for irradiating light to the liquid crystal panel, is required. Such a backlight unit is divided into an edge method and a direct method according to the installed position.

Here, the edge-type backlight unit is formed on both sides of the liquid crystal panel to induce light generated from the lamp and the lamp toward the liquid crystal panel, the light guide plate formed in the lower liquid crystal panel, and the lamp housing formed on the side of the lamp to protect the lamp And an optical sheet formed on the lamp housing and the light guide plate to uniformly transmit light toward the liquid crystal panel.

In the conventional backlight-type backlight unit, after 10 minutes to 20 minutes at room temperature, heat generated from the lamp is transferred to the optical sheet through a lamp housing provided to protect the lamp, thereby causing wrinkles on the optical sheet adjacent to the lamp. Wrinkle occurs.

In addition, when vibration is applied to an optical sheet in which a plurality of layers are stacked on the lamp housing and the light guide plate, friction and splitting may occur between the non-fixed sheets. In addition, the vibration causes the light guide plates inserted into both sides of the lamp housing to penetrate into the lamp housing, thereby causing a problem of lamp cracks provided in the lamp housing.

In order to solve the above problems, the present invention provides a backlight unit and a liquid crystal display using the same to improve the light guide plate and the lamp housing to prevent light leakage and wrinkles in the optical sheet and to prevent damage to the lamp by vibration. have.

The backlight unit according to the present invention includes a bottom cover; A lamp formed on one side or both sides of the bottom cover; A light guide plate for inducing light of the lamp; A lamp housing protecting the lamp and condensing the light of the lamp and supplying the light to the light guide plate; A plurality of first optical sheets having a first area accommodated and stacked on the light guide plate; And a plurality of second optical sheets having a second area stored on the lamp housing and laminated on the plurality of first optical sheets.

In the backlight unit and the liquid crystal display using the same, the first and second receiving grooves are formed in the light guide plate and the lamp housing, thereby preventing the separation of the plurality of optical sheets and the separation of the plurality of optical sheets due to vibration. And wrinkles by heat transfer can be prevented.

In addition, by forming the size of the lamp housing in the same or smaller than the size of the light guide plate, it is possible to prevent the lamp breakage caused by the light guide plate penetrates into the lamp housing during vibration.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings and embodiments.

1 is a cross-sectional view illustrating a backlight unit according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a backlight unit according to a second embodiment of the present invention.

Referring to Figure 1, the bottom cover 102 and the bottom cover (bottom cover) 102 is configured to include a reflective sheet 104 on the back. Here, the reflective sheet 104 reflects the light of the light guide plate 108 which guides the light to the lamp 106 to the optical sheet. In this case, the reflective sheet 104 is formed on the front surface of the bottom cover 102, or as shown in Figure 2, is formed larger than the light guide plate 108 to prevent light leakage.

The lamp 106 is disposed on one side or both sides of the bottom cover 102. Here, the lamp 106 emits light by receiving power from two different electrode parts (not shown). In this case, the lamp 106 may be any one of an External Electrode Fluorescent Lamp (EEFL), a Cold Cathode Fluorescent Lamp (CCFL), an External Internal Fluorescent Lamp (EIFL), and a Hot Cathode Fluorescent Lamp (HCFL).

The light guide plate 108 is disposed on the bottom cover 102 to which the reflective sheet 104 is attached. Here, the light guide plate 108 scatters the light incident from the lamp 104 and exits to the front surface. In this case, the light guide plate 108 may be formed of a plastic, resin, or heat resistant glass material such as PolyMethylMethacrylAte (PMMA) in a flat or wedge type.

In addition, the light guide plate 108 includes a first accommodating groove 114 to be accommodated in combination with the plurality of first optical sheets 112 having a first area.

The first accommodating groove 114 is formed such that a plurality of first optical sheets 112 having a first area may be stacked on the light guide plate 108. In this case, the first accommodating groove 114 may be joined with the plurality of first optical sheets 112 to prevent wrinkles and wrinkles of the plurality of first optical sheets 112 due to vibration and impact.

The plurality of first optical sheets 112 are bonded and stacked on the first receiving grooves 114 formed on the light guide plate 108. Here, the plurality of first optical sheets 112 includes a diffusion plate 112a and a diffusion sheet 112b.

The diffusion plate 112a is stacked in the first receiving groove 114 of the light guide plate 108. Here, the diffusion plate 112a scatters the light from the lamp 106 to diffuse the light of the light guide plate 108 emitted to the front surface.

The diffusion sheet 112b is stacked on the diffusion plate 112a stacked in the first receiving groove 114 of the light guide plate 108. Here, the diffusion sheet 112b supplies the light diffused from the diffusion plate 112a to the plurality of second optical sheets 116 so that the overall luminance is uniform.

The lamp housing 110 is disposed at the side of the light guide plate 108 on the bottom cover 104. Here, the lamp housing 110 protects the lamp 106 and condenses the light of the lamp 106 and supplies it to the light guide plate 108. At this time, the height of the lamp housing 110 is formed so as not to be equal to or greater than the height of the light guide plate 108 to prevent cracks in the lamp due to vibration.

In addition, the lamp housing 110 includes a second accommodating groove 118 to be accommodated in combination with the second optical sheet 116 having the second area.

The second accommodating groove 118 is formed such that a plurality of second optical sheets 116 having a second area may be stacked in the lamp housing 110. In this case, the second accommodating groove 118 may be combined with the plurality of second optical sheets 116 to prevent wrinkles and wrinkles of the plurality of second optical sheets 116 due to vibration and impact.

The plurality of second optical sheets 116 are laminated on the lamp housing 110 by being joined to the second receiving grooves 118. Here, the plurality of second optical sheets 116 is arranged to change the light diffused from the plurality of first optical sheets 112 in the vertical direction. In this case, the plurality of second optical sheets 116 is composed of a plurality of prism sheets 116a and 116b, and includes a protective sheet (not shown) for protecting the plurality of second optical sheets 116.

In addition, the plurality of second optical sheets 116 may have a triangular mountain shape or a cross-section having a streamline shape, which is not shown in the cross section, to increase the front brightness or to condense and diffuse light to increase the brightness.

The backlight unit according to the first exemplary embodiment of the present invention forms the first and second accommodating grooves 114 and 118 in the light guide plate and the lamp housings 108 and 110, thereby causing the optical sheets 112 and 116 to be vibrated. The separation phenomenon and the phenomenon that the optical sheets 112 and 116 are separated can be prevented, and wrinkles due to heat transfer can be prevented.

In addition, by forming the size of the lamp housing 110 in the same or smaller than the size of the light guide plate 108, it is possible to prevent the lamp breakage caused by the light guide plate 108 to enter the lamp housing 102 during vibration.

3 is a diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view illustrating II ′ in the liquid crystal display of FIG. 3 according to an exemplary embodiment of the present invention.

3 and 4, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel 204 for displaying an image by adjusting light transmittance, and a backlight unit for irradiating light to the liquid crystal panel 204. 100, the panel guide 202 disposed on the bottom cover 102 and the lamp housing 110 to support the liquid crystal panel 204, the front edge of the liquid crystal panel 204, the panel guide and the bottom cover 202, And a top cover 214 surrounding the side of 102.

The liquid crystal panel 204 includes a transistor array substrate and a color filter array substrate bonded to each other, a spacer (not shown) for maintaining a constant cell gap between the two array substrates, and a liquid crystal layer filled in the liquid crystal space provided by the spacer. It is configured to include (not shown). At this time, the liquid crystal panel 204 displays an image by adjusting the light transmittance of the liquid crystal.

The color filter array substrate includes a color filter, a common electrode, a black matrix, and the like. Here, the common electrode may be formed on the transistor array substrate.

The transistor array substrate is formed in a region defined by a plurality of data lines (not shown) and a plurality of gate lines (not shown), and is connected to a thin film transistor (not shown) connected to the gate line and the data line, and connected to the thin film transistor. It is configured to include a liquid crystal cell (not shown).

In addition, a lower polarizing film 210 facing the plurality of second optical sheets 116 is attached to the rear surface of the transistor array substrate. The lower polarizing film 210 polarizes the light irradiated from the optical sheets 116 and 112. At this time, the transmission axis of the lower polarizing film 210 is disposed at a predetermined angle to match the alignment direction of the liquid crystal layer.

The upper polarizing film 212 is attached to the rear surface of the color filter array substrate. The upper polarizing film 212 polarizes light passing through the liquid crystal layer and the color filter array substrate. In this case, the transmission axis of the upper polarizing film 212 is disposed to be perpendicular to the transmission axis of the lower polarizing film 210.

The panel guide 202 is stacked on the lamp housing 110 and the bottom cover 102, and the top cover 214 of the rectangular frame having the edge of the liquid crystal panel 204 is formed on the panel guide 202 and the bottom cover. 102 is assembled and fastened.

The top cover 214 surrounds the front edge of the liquid crystal panel 204 disposed on the panel guide 102 and the side surface of the bottom cover 102. To this end, the top cover 214 includes a non-display area, that is, a flat portion covering the edges of the liquid crystal panel 204, and a side portion bent vertically from the flat portion to surround the side of the bottom cover 102. It is configured by.

As described above, the liquid crystal display using the backlight according to the first exemplary embodiment of the present invention forms the first and second accommodating grooves 114 and 118 in the light guide plate and the lamp housings 108 and 110, thereby providing a plurality of optical signals due to vibration. Separation of the sheets 112 and 116 and separation of the plurality of optical sheets 112 and 116 may be prevented, and wrinkles may be prevented due to heat transfer.

In addition, by forming a size in the lamp housing 110 the same as or smaller than the size of the light guide plate, it is possible to prevent the lamp breakage caused by the light guide plate 108 to enter the lamp housing 102.

The liquid crystal display device is not limited to the backlight unit according to the first embodiment of the present invention, but may be applied to the backlight unit according to the second embodiment.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a cross-sectional view showing a backlight unit according to a first embodiment of the present invention.

2 is a cross-sectional view of a backlight unit according to a second embodiment of the present invention;

3 illustrates a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating the liquid crystal display of FIG. 3 according to an exemplary embodiment of the present invention. FIG.

Claims (8)

A bottom cover; A lamp formed on one side or both sides of the bottom cover; A light guide plate for inducing light of the lamp; A lamp housing protecting the lamp and condensing the light of the lamp and supplying the light to the light guide plate; A plurality of first optical sheets having a first area accommodated and stacked on the light guide plate; And And a plurality of second optical sheets having a second area that is received on the lamp housing and laminated on the plurality of first optical sheets. The method of claim 1, The light guide plate is a backlight unit, characterized in that the first accommodating groove is formed to be accommodated in combination with the first optical sheet. The method of claim 1, The lamp housing is a backlight unit, characterized in that the second accommodating groove is formed to be accommodated in combination with the second optical sheet. The method of claim 1, And a height of the lamp housing is equal to or lower than a height of the light guide plate to prevent breakage of the lamp. The method of claim 1, And a reflective sheet for reflecting light of the light guide plate from a rear surface of the bottom cover. The method of claim 5, The reflective sheet is a backlight unit, characterized in that formed larger than the size of the light guide plate to prevent light leakage. A liquid crystal panel which displays an image by adjusting light transmittance; A liquid crystal display device comprising any one of the backlight units of claim 1 to irradiate light onto the liquid crystal panel. The method of claim 7, wherein A panel guide disposed on a bottom cover to support the liquid crystal panel; And a top cover surrounding the front edge of the liquid crystal panel and the side surfaces of the panel guide and the bottom cover.
KR1020070096571A 2007-09-21 2007-09-21 Backlight unit and liquid cristal display device usimg the same KR20090030903A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020070096571A KR20090030903A (en) 2007-09-21 2007-09-21 Backlight unit and liquid cristal display device usimg the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020070096571A KR20090030903A (en) 2007-09-21 2007-09-21 Backlight unit and liquid cristal display device usimg the same

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KR20090030903A true KR20090030903A (en) 2009-03-25

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10451911B2 (en) 2017-02-28 2019-10-22 Microsoft Technology Licensing, Llc Display device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10451911B2 (en) 2017-02-28 2019-10-22 Microsoft Technology Licensing, Llc Display device
US10473967B2 (en) 2017-02-28 2019-11-12 Microsoft Technology Licensing, Llc Display device

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